get_station_observation

Instructions

Implementation Reference

• src/weather_edge_mcp/mcp_server.py:70-78 (handler)

  MCP tool handler for get_station_observation - decorates function with @mcp.tool(), calls get_city, fetch_station_observation, and format_station_observation.

  @mcp.tool()
  def get_station_observation(city: str) -> str:
      """Get the latest METAR observation from the settlement station for one city.
  
      Args:
          city: One of nyc, chicago, denver, miami, la.
      """
      cfg = get_city(city)
      return format_station_observation(cfg.key, _run(fetch_station_observation(cfg.key)))

• src/weather_edge_mcp/core.py:135-158 (helper)

  Async function that fetches METAR observation data from aviationweather.gov API, parses the JSON response, and returns transformed result with temp in °C and °F, wind speed, station info, and raw METAR text.

  async def fetch_station_observation(city_key: str) -> dict[str, Any]:
      cached = get_cached(f"station_{city_key}")
      if cached:
          return cached
      cfg = CITIES[city_key]
      async with httpx.AsyncClient(timeout=10) as client:
          resp = await client.get(AVIATION_WEATHER_BASE, params={"ids": cfg.metar_station, "format": "json"})
          resp.raise_for_status()
          payload = resp.json()
          if not payload:
              raise RuntimeError(f"No METAR observation for {cfg.metar_station}")
          obs = payload[0]
          result = {
              "city": city_key,
              "station": cfg.station,
              "icao": cfg.metar_station,
              "observed_at": obs.get("obsTime") or obs.get("observationTime") or "",
              "temp_c": obs.get("temp") if obs.get("temp") is not None else obs.get("tempC"),
              "wind_speed_kt": obs.get("wspd") or obs.get("windSpeed"),
              "raw": obs.get("rawOb") or obs.get("rawText") or "",
          }
          result["temp_f"] = round((float(result["temp_c"]) * 9 / 5) + 32, 1) if result["temp_c"] is not None else None
          set_cached(f"station_{city_key}", result)
          return result

• src/weather_edge_mcp/core.py:287-295 (helper)

  Formats the station observation data dict into a human-readable string output (station name, ICAO, timestamp, temp °F, wind, raw METAR).

  def format_station_observation(city_key: str, obs: dict[str, Any]) -> str:
      return (
          f"# Station Observation — {CITIES[city_key].label}\n\n"
          f"Station: {obs['station']} ({obs['icao']})\n"
          f"Observed at: {obs['observed_at']}\n"
          f"Temperature: {obs['temp_f']}°F\n"
          f"Wind: {obs['wind_speed_kt']} kt\n"
          f"Raw METAR: {obs['raw']}"
      )

• src/weather_edge_mcp/core.py:19-39 (schema)

  CityConfig dataclass defines the schema including metar_station field used to identify the settlement station for observations.

  @dataclass(frozen=True)
  class CityConfig:
      key: str
      label: str
      station: str
      metar_station: str
      nws_office: str
      nws_grid_x: int
      nws_grid_y: int
      kalshi_series: str
      sigma: float
      forecast_bias: float
  
  
  CITIES: dict[str, CityConfig] = {
      "nyc": CityConfig("nyc", "New York City", "Central Park", "KNYC", "OKX", 33, 37, "KXHIGHNY", 3.0, -1.0),
      "chicago": CityConfig("chicago", "Chicago", "Midway", "KMDW", "LOT", 76, 73, "KXHIGHCHI", 3.0, -0.5),
      "denver": CityConfig("denver", "Denver", "Denver", "KDEN", "BOU", 62, 60, "KXHIGHDEN", 4.0, 0.0),
      "miami": CityConfig("miami", "Miami", "MIA Airport", "KMIA", "MFL", 75, 54, "KXHIGHMIA", 3.5, -3.0),
      "la": CityConfig("la", "Los Angeles", "Los Angeles Downtown", "KLAX", "LOX", 154, 44, "HIGHLA", 3.5, 0.0),
  }

• src/weather_edge_mcp/mcp_server.py:21-29 (registration)

  FastMCP server instantiation with 'weather-edge' name and instructions mentioning get_station_observation tool.

  mcp = FastMCP(
      name="weather-edge",
      instructions=(
          "Weather Edge MCP Server for calibrated Kalshi weather-market intelligence. "
          "Use list_cities for supported markets, get_weather_signals for one city, "
          "get_all_signals for a full scan, get_forecast for raw forecast context, and "
          "get_station_observation for live settlement-station readings."
      ),
  )